Underglazing Pottery | Glazing Tips Tools and Ideas
Underglazing pottery is a creative way to add designs and colors to your Pottery. The underglaze comes out through the actual glaze layer and forms beautiful patterns that give the pottery a professionally made look, adding character and depth to the surface.
There are plenty of techniques to apply underglazes, and you can make any design from simple strokes to intricate floral patterns.
If you’re a new Potter or don’t have much experience with Decorating Pottery, learning about the composition, types, and methods of using Underglazes can help you bring to life the imaginative and artistic designs in your head.
To become a successful Potter and master the art of Underglazing, you must first learn what underglazes actually are, and what kinds of underglazes are available these days.
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What is Underglaze?
Underglazing is much like painting and drawing, giving you the ability to create gorgeous designs that cover pottery pieces. They’re commonly used under transparent glazes, but they can be used under light-colored, unsaturated and light-hue glazes.
But what exactly are Underglazes? Any decoration in a fluid form (mostly) that can be applied to a pottery surface before the glaze layer is called underglaze. This means that engobes, stains, slips, and all products marketed as underglazes fall into this category.
Basic Underglazes consist of Colorants, Clay, Water, and a small amount of frit. Frit is silica and flux (an oxide).
What is Slip?
In simple words, Slips are just, Thin Clay, Water, and Colorants – also known as Stains and Pigments. It has been a popular way to decorate pottery since ancient times. Technically Slip that can be applied to pottery at any stage, but the leather hard stage is the most popular and recommended. Due to the number of colors available in naturally occurring clay, slips can add distinctive, vibrant colors to the pottery they’re applied on.
There are a large number of techniques used to apply slips ranging from simply brushed strokes to paste-on-paste embellishments. Even complex abstract artworks are done on pottery using slips.
For more detailed information on slips and underglazes read: Is Colored Slip the Same As Underglaze?
Underglaze Products
Underglaze has often been referred to as a fancy version of slip. The real difference is commercial underglazes contain frits that reduce shrinkage which allows them to be applied to greenware and bisque ware.
Here are some Underglazes I use and recommend trying
Speedball Liquid Underglaze:
Speedball is the best, all-around liquid underglaze having great pigmentation. When it comes to having a choice of colors, this set of 2-ounce bottles has a beautiful array of twelve colors. I found these underglazes give you great coverage on Greenware and Bisque ware.
Sax True Flow Underglaze Set:
These are concentrated liquid colors that leave an opaque finish. They can be used to give both shiny effects and matte effects. You get nice coverage from True Flow Underglazes. Just one coat will cover depending on how thick you apply these underglazes, but 2 to 3 coats are recommended
Amaco Velvet Semi-Translucent Underglaze Set:
These Semi-Translucents are sprayable, and mixable colors give you a soft, velvety look to both Greenware and Bisqueware. Amaco Velvet underglaze has an excellent choice of colors that create beautiful designs, which makes the set of 12 perfect for mixing and matching.
For more information on the Speedball, Sax True Flow, and the Amaco Velvet Semi-Translucent Underglaze sets listed above, Go to my Recommended Glazes Page.
How to Apply Underglaze
Underglaze is similar to paint, except the canvas is Pottery. Its main use is to create patterns, pictures, and designs. There are many ways to apply underglaze to your pottery. The most popular way is to brush it on. You can also use a sponge, pour, dip, spray, bubble, splatter, pencils, and markers.
Using Underglaze also gives you more fluid to work with during designing, which acts as an advantage. If you want extra color detail, you could apply an underglaze design on a clay mold, bisque-fire it, and proceed to add more colors and design layers of underglaze before applying a final transparent glaze coat. For more tips on glazing, visit 27 Glazing Tips for you.
Before applying an underglaze, you should read the directions on the product’s label. Nearly all commercially manufactured underglazes can be used on Wet Clay, Leather hard, Bone-dry Greenware, and Bisque ware.
Underglazing the Greenware
There are a number of benefits of applying underglaze to greenware.
One significant advantage of applying underglazes to greenware is the ability to touch up the design after the initial firing. If the color was diminished during the firing, or if there are any imperfections, potters can reapply or touch up the underglaze and refire the pottery. This provides an opportunity to refine the final product.
Applying underglaze at the greenware stage allows artists to modify their designs early in the creation process. You can blend the underglaze when the clay is in the Plastic (workable) Stage to create effects like marbling or the Sgraffito technique when the clay is in the Leather Hard Stage.
When fired, the underglaze becomes part of the clay body, which is now ceramic. This means the underglaze will not smear when the pottery is covered with a transparent or translucent glaze to add a shiny, satin, or matte finish to enhance and protect the underglaze.
Try avoiding going over the underglaze and correcting it before it dries. Be very careful, and don’t nudge your hand or smudge the art. Greenware clay quickly absorbs underglaze. Because of this, correcting any inconsistency may be harder.
When working on bone-dry greenware, be very careful because it is in its most fragile state.
Underglaze Your Bisque Ware
Just like Underglazing greenware has its perks, Underglazing bisque-ware also has its own. Bisque-fired pottery is firmer and much less fragile. Being firm also means it will withstand the pressure from pottery tools, and you can Underglaze using Crayons, Pens, and Pencils without hurting the surface and making incisions and dents or chipping. The design tends to be more precise and cleaner.
Underglaze tends to adhere better to bisqueware than to greenware. The porous surface of bisqueware absorbs the underglaze more effectively, resulting in a strong bond. Bisqueware allows for more controlled absorption of the underglaze, leading to more consistent results in the final color after the glaze firing.
Depending on the color saturation, you might need to apply 1 to 3 coats. After you’re done, apply a clear glaze topcoat and put the pottery in a Kiln.
For more detailed information on underglaze applications, go to Applying Underglaze on Greenware vs Bisqueware – Which Is Best. In the article, I also give a list of methods and which stages of clay it is best to apply to.
Get Creative with Colors!
Commercial Underglazes are now manufactured in many different colors. They are composed of clay slips, many colorants, and frit.
There are a number of ways to apply them together and get wonderful designs. You can Mix the Colors Together before applying them. Apply layers to get a brighter and more saturated tone. You can also layer contrasting colors.
Underglazing is definitely a fun part of decorating your pottery. Keep in mind you may need to layer the colors as a single coat can be very soft and less pronounced. Here are just a few ways you can use your Underglaze:
Underglazing Ideas and Tools
There are many ways to apply underglaze to your pottery. Here are just a few ways to choose from:
Brushing
This technique is one of the most popular ways to apply underglaze. You can use any size brush you want to obtain the design you want to create, from a small detail brush to a large fan brush.
Even if you can’t draw or paint, you can create beautiful abstract designs. For more information, see Different Brushes you can use for Glazing.
Sgraffito
Another popular technique is where the potter carves through the glaze layers to reveal the clay body below. This form of abstract, high-contrast art isn’t too hard to achieve. Just apply one or more underglaze layers to a wet or leather hard pottery piece and wait for the Underglaze to Dry and carve with Sgraffito and Detailing Tools carving tools. You can also use other caving tools to create your own unique design.
If you are applying more than one color, let the underglaze dry before you apply another coat. Don’t let your pottery become bone-dry because you will not be able to carve in it. The best time to start carving is when pottery is leather-dry.
Sponging
You can get pretty creative with a Sponge and some Underglaze. To get a few tips and ideas visit my Sponge Glazing article for more detailed information on this technique.
Transfers / Decals
Transfers and decals are another great way to decorate your clay. They consist of underglaze colors printed onto paper or tissue and can be applied to various stages of clay, including leather-hard and bisque ware.
Once the Underglaze is damp, place the paper on your leather hard Pottery with the Underglaze facing down. Then, rub the image gently with your damp sponge. Let the image dry and carefully peel off. If you use too much water, your image may blur. For a step-by-step Video, check out How To Apply Sanbao Ceramic Underglaze Decals.
Watercolor
Watercolor underglazes are another great way to decorate your pottery, giving your pottery that watercolor effect.
Watercolors Underglazes can be used on leather hard and dry greenware but show the best results on bisque-fired pottery. Watercolor underglazes blend without a hassle and give more dimension to pottery pieces. The colors pop below the clear glaze and give amazing textures.
Bubble Underglazing
Bubble Underglazing is another fun way to decorate your pottery. The Bubble glazing process involves mixing underglaze with soap and water and then blowing through a straw to create bubbles. These bubbles are then gently transferred onto the surface of the pottery.
You can read How To Bubble Glaze for more detailed information on this technique.
Marbling Underglaze
Marbling with Underglaze can be successfully applied during both the Greenware and Bisqueware phases of clay processing.
For techniques such as the shave cream method or the split cup method, it is best to apply this on Bisqueware. This ensures that the underglaze adheres effectively to the clay’s surface.
To create the marble effect, you can go to Underglazing with Split Cups For a Marbling Effect – A Step-by-Step Guide
Pencil
These Pencils are great for drawing elaborate designs and give rich, vibrant colors that pop up from beneath the glaze layer.
For those of you who would much rather draw something, Underglaze Pencils are a great option. They show through glaze layers and allow space for detailing and defining. You can use underglaze pencils to write names and notes as well. Remember only to use underglaze pencils on bisque-fired pottery.
👇 Underglaze Pencils 👇
Conclusion
Underglazing is another fun way to decorate your pottery. The amount of different techniques you can choose from is great for potters in all different stages of skill levels. Which tool, technique, and colors are you going to use?
From the Beginner potters to the Experienced, there is something for everyone when it comes to Underglazing. There is no limit to what you can create.